topic Re: Lens focus ring sticky degrading rubber in EF & RF Lenses

Focus rings have sticky degrading rubber across multiple lenses

bobakman — Tue, 25 Feb 2025 14:27:11 GMT

I have EF lenses some that were included in my kits and another the 70-300 that I purchased separately.
I have noticed that the rubber outer covering of the focus rings only not the rubber on the body of the lenses, have deteriorated becoming sticky and soft with age.
These lenses have been stored when not in use in either my camera gear bag or separate lens cases.
These are the specific lenses and date of purchase below.
I am the original owner and have always had clean hands when using these lenses never any chemicals such as Insect repellant or perfumes or cologne on my hands.
I have submitted service requests for all of these lenses to Canon and am awaiting a resolution.
Has anyone else had this issue with their Canon Lenses?
Video link here: https://youtu.be/tK24Y3TMTm4
Thanks, Bob

EF-S 18-135mm f/3.5-5.6 IS STM. 2013-01-22

EF-S 18-55mm f/3.5-5.6 IS STM. 2013-06-03

EF 70-300mm f/4-5.6 IS USM. 2013-06-03

Re: Lens focus ring sticky degrading rubber

deebatman316 — Mon, 24 Feb 2025 19:03:10 GMT

I’ve never had an issue with sticky rubber on lenses. My oldest lens which dates back to the 80s doesn’t suffer from this. My old EOS 40D body is sticky though. I also believe that Canon has discontinued support on the EF 70-300mm Mark I USM lens.

Re: Lens focus ring sticky degrading rubber

normadel — Mon, 24 Feb 2025 19:17:50 GMT

Use Isopropyl (rubbing) alcohol to clean the rubber parts.

Other chemicals can damage the rubber.

The problem has nothing to do with cleanliness or storage in cases or not. It's an age and exposure to air thing. Lots of rubber-type coatings are subject to it....camera bodies, lenses, laptop computers, hand tools etc. Some coatings do it, some don't, to varying degrees.

Re: Lens focus ring sticky degrading rubber

bobakman — Mon, 24 Feb 2025 19:37:37 GMT

Yes the 70-300 has reached "The end of its service life." according to the Canon website. Though the end of its useful life has yet to be reached. I still consider this to be a manufacturing defect due to poor materials selection of the specific rubber that was used on the focus rings. The rubber currently that was used on the lens bodies is not exhibiting this same issue.
I was E-Mailed by Canon and told to submit a repair request which I did and the quote I received for repair of both lenses still within their service life is $420.51.
I will reach out to Canon again and see if they will consider "particapating in the repair."
It can never hurt to ask. Canon has always done right by me and I am hoping this will be no different.
Bob

Re: Lens focus ring sticky degrading rubber

ebiggs1 — Mon, 24 Feb 2025 20:36:55 GMT

"Use Isopropyl (rubbing) alcohol to clean the rubber parts."

That won't help. I have seen this happen on several different lens models. Replacement is the only real fix. You can pit tape around it. Something like tennis racket handle gripe tape will work. Sorta!

Re: Lens focus ring sticky degrading rubber

bobakman — Mon, 24 Feb 2025 21:20:50 GMT

Exactly what I am thinking either replacing the rubber or placing another cover material over it, leaning towards total replacement anything else is just temporary.
I see the same effect on rubber belts in stereo systems I have repaired. The rubber actually turns into a semi liquid almost like a grease the rubber on my two lenses is getting that way when it gets shiny it gets softer and all the alcohol does at that point is remove rubber until none is eventually left sadly.
Bob

Re: Lens focus ring sticky degrading rubber

March411 — Tue, 25 Feb 2025 03:13:03 GMT

bobakman, I searched New original rubber For CANON EF 70-300mm f/4-5.6L IS USM Zoom and found replacements on eBay and a couple other sites for around $35. Either you can do the replace or buy the part and see if a local shop can take care of it. Seems like a simple fix and for far less then $420.

Re: Lens focus ring sticky degrading rubber

deebatman316 — Tue, 25 Feb 2025 03:26:40 GMT

The OP doesn’t have the L model of the lens. Instead they have the original model from 2005. This lens uses a cheaper Micro USM AF motor and doesn’t support full time manual focus. It is also a reverse zoom lens too.

Re: Lens focus ring sticky degrading rubber

bobakman — Tue, 25 Feb 2025 03:28:18 GMT

March411, thanks for that, it never crossed my mind to look for replacements this sounds like the best option.
Bob

Re: Lens focus ring sticky degrading rubber

March411 — Tue, 25 Feb 2025 03:59:15 GMT

Thanks deebatman316! I wasn't real sure but a search of his exact lens will find the part he needs to do the repair or get a repair center to knock it out.

Re: Lens focus ring sticky degrading rubber

bobakman — Tue, 25 Feb 2025 04:22:39 GMT

I actually used Isopropyl alcohol to remove the residue so I could order those rubber pieces and found out that the focus rings are NOT rubber but hard plastic. Pretty bad though when hard plastic starts turning soft on the surface.
This would explain though why the rubber on the body is not affected.
So the pieces on Ebay would basically stretch over I assume the existing focus rings so if they do get sticky again they would be covered and not exposed.
Bob

Re: Lens focus ring sticky degrading rubber

March411 — Tue, 25 Feb 2025 15:14:30 GMT

I watched a disassembly of the lens deebatman316 and understand what you are telling me, the zoom ring is a single piece with a plastic collar. You would have to tear down the lens to replace it.

Re: Lens focus ring sticky degrading rubber

ebiggs1 — Tue, 25 Feb 2025 15:20:42 GMT

Bob tyr the tennis racket grip tape it will last a long time.

Re: Lens focus ring sticky degrading rubber

justadude — Tue, 25 Feb 2025 15:46:01 GMT

"Use Isopropyl (rubbing) alcohol to clean the rubber parts."

I was given an older Tamron 70-300mm lens years ago that was getting sticky on the rubber ring. He told me if I wanted to bother cleaning it up, I could have it. Said he heard rubbing alcohol was the way to go. So I tried it, but all it did was gum it up even worse. So either he tried to do the same years earlier, then it sat and got worse, or there rubber just deteriorated to the point of no return.

Re: Lens focus ring sticky degrading rubber

March411 — Tue, 25 Feb 2025 16:06:27 GMT

Tennis racket grip tape does appear to be the best bet given the value of the lens. And black is available so this might be the easiest way to get around the stickiness.

Re: Lens focus ring sticky degrading rubber

bobakman — Tue, 25 Feb 2025 16:26:17 GMT

I was able to get the ring back to its non-sticky hard plastic self without it turning into gum. I used 90% not the usual 70% dries faster due to only 10% water. What I did not want to do and the danger is real, is have the gooey mess with the solvent making its way in-between the body of the lens and the ring into the focus ring internals. At this point the sports tape/tennis racket tape looks to be the best option now that I have cleaned it.
Thank you ALL for your comments and ideas you have been very helpful.
Bob

Re: Lens focus ring sticky degrading rubber

bobakman — Tue, 25 Feb 2025 19:06:00 GMT

All three of my lenses have been repaired with the tennis racket wrap placed over the rings. I cut mine about 1 cm for the larger rings a little narrower than the actual focus ring so that wouldn’t overlap on the edges. I used a drop of superglue with the first lap and then finished the wrap with another drop of superglue because the stuff does not stick very well to itself. You pull it slightly not enough to stretch it too narrow and it seems to be in place well. Nice thing about this it can always be redone anytime.
You will need a sharp instrument to cut the wrap, I used a scalpel and a good straightedge and a tube of good quality superglue.
Bob

Bob

Re: Focus rings have sticky degrading rubber across multiple lenses

March411 — Tue, 25 Feb 2025 19:14:22 GMT

They look good, it turned out real nice and the tennis tape will give you a nice grip.

ebiggs, great thought on the factory modification.